A negative C-plate compensation film used in common liquid crystal displays (LCDs) is disclosed in U.S. Pat. No. 4,889,412. A main function of the negative C-plate compensation film is to compensate for the black state of vertically aligned LCDs (VA-LCDs) under no voltage application. However, VA-LCDs including only a negative C-plate compensation film have a disadvantage of light leakage at an oblique angle due to imperfect viewing angle compensation.
Combination of a negative C-plate compensation film and an A-plate compensation film is disclosed in U.S. Pat. No. 6,141,075. According to the technology disclosed in this patent, good viewing angle compensation of the black state of a VA-LCD under no voltage application is achieved. However, for perfect compensation, enhancements in contrast characteristics and color change for front view and oblique angle view are required.